Also, it is pretty possible for Disney to release a box set of the Original Trilogy but for standalone releases, only The Empire Strikes Back and Return of the Jedi will have them while Fox releases Star Wars.

Disney can include Star Wars in a box set as long as they’re doing it under license from Fox.

They did it with The Incredible Hulk (Universal Studios) in the Marvel Cinematic Universe: Phase One box set and also with Lupin III: The Castle of Cagliostro (Eastern Star Media) in The Collected Works of Hayao Miyazaki box set but Disney never did a standalone release of either The Incredible Hulk or Lupin III: The Castle of Cagliostro.

They can also do their own disc for Star Wars.
While The Incredible Hulk only copy-pasted the standalone Universal disc in the MCU: Phase One box set, the Lupin III: The Castle of Cagliostro disc in the Hayao Miyazaki box set is different than the standalone Eastern Star Media disc.

Maybe Disney can release the Original Unaltered Trilogy box set in Ultra HD Blu-ray, Blu-ray and DVD as well standalone versions of The Empire Strikes Back and Return of the Jedi in said formats while Fox does a standalone release of Star Wars to go along the Disney releases.